package com.mmall.common;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

/**
 * Created by Administrator on 2017/7/27.
 */
public class TokenCache {
    private static Logger logger = LoggerFactory.getLogger(TokenCache.class);

    public static final String TOKEN_PREFIX = "token_";
    //LRU算法
    //LRU（Least recently used，最近最少使用）算法根据数据的历史访问记录来进行淘汰数据，其核心思想是“如果数据最近被访问过，那么将来被访问的几率也更高
    private static LoadingCache<String,String> localCache = CacheBuilder.newBuilder().initialCapacity(1000).maximumSize(10000)
                    .expireAfterAccess(12, TimeUnit.HOURS)
                    .build(new CacheLoader<String, String>() {
                       //默认的数据加载实现，当调用get取值的时候，如果key没有对应的值，就调用这个方法进行加载
                        @Override
                        public String load(String s) throws Exception {
                            return "null";
                        }
                    });

    public static void setKey(String key,String value){
        localCache.put(key,value);
    }

    public static String getKey(String key){
        String value = null;

        try {
            value = localCache.get(key);
            if ("null".equals(value)){
                return null;
            }
            return value;
        } catch (ExecutionException e) {
            logger.error("localCache get error",e);
        }
        return null;
    }

}
